Petrology is a field of science in which scientists study the compositions of rocks and minerals and interpret their geologic history. A common graph petrologists use is the “pyroxene quadrilateral.” These graphs, like photos of space, can reveal an understanding of the remotest parts of the solar system.

While we can measure properties of these upper layers using ground-based instruments, satellite-borne remote sensing instruments can give us a more frequent, global, and often higher spatial resolution perspective. And that is precisely what NASA’s Global-scale Observations of the Limb and Disk (GOLD) mission will deliver.